In an election, half the electors voted for candidate and two-thirds voted for candidate . 10 electors voted for both and . 6 electors voted for neither nor . How many electors were there?
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1 mark, −0.25MathematicsCombinatorics and countingInclusion-exclusion and complementary countingModerateabout 1 min
JNU SSS 2013 Question 82: Combinatorics and counting
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In an election, half the electors voted for candidate A and two-thirds voted for candidate B. 10 electors voted for both A and B. 6 electors voted for neither A nor B. How many electors were there? (A) 18 (B) 24 (C) 36 (D) None of the above
Combinatorics and counting has come up 24 times in 5 exams since 2009.
What this question tests
This question is on Inclusion-exclusion and complementary counting, part of Combinatorics and counting in Mathematics.
Counting by adding and removing overlaps, or by counting what is not wanted.
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